Having spent the past decade pursuing a transport policy of four wheels rich, two wheels poor, the Chinese government has suddenly rediscovered the environmental and health benefits of the bicycle.

The construction ministry announced on Thursday that any bike lanes that have been narrowed or destroyed to make way for cars in recent years must be returned to their original glory. This followed orders on Tuesday that all civil servants should cycle to work or take public transport to reduce the smog that chokes most city streets and urban lungs.

Qiu Baoxing, a vice-minister with the Ministry of Construction, said it was important for China to retain its title as the "kingdom of bicycles," according to a report by the official Xinhua news agency.

The reputation was well deserved 25 years ago, when Beijing was famous for its swarms of cyclists. But a quarter-century of breakneck industrial development has utterly transformed the streets of almost every city. China has become infatuated with the car, which is seen as a symbol of success and modernity.

Qiu was quoted as saying that the number of vehicles on China's roads has increased more than twenty-fold since 1978 to 27m. Within 15 years, he predicted, it could rise to more than 130m - which still represents only one car for every 10 people.

In Beijing alone, it is estimated that 1,000 new cars every day are added to an already appalling traffic snarl-up. Until now, urban planners have tried to make room for these economic engines by building thousands of miles of multi-lane roads, often at the expense of bike lanes.

Estimates of the number of bicycles in the city range from 4m to 10m. But transport analysts say the average Beijinger travels 60% less by bike than 10 years ago and those journeys are becoming dirtier and more dangerous.

The apparent shift of focus comes at the start of a new five-year economic plan in which the government says its priority is to improve the environment and conserve energy. Earlier this month, the World Bank issued a new report calling on China to invest more in public transport rather than focusing on the construction of new highways for cars.

But, as other countries have found out, having become addicted to the economy to cars, it will not be easy for China to kick the motoring habit.